/*
 * Copyright (c) 2010-2013 Isode Limited.
 * All rights reserved.
 * See the COPYING file for more information.
 */

#include <Swiften/Base/Platform.h>

#include <cassert>
#include <algorithm>
#include <sstream>
#include <iomanip>
#ifdef SWIFTEN_PLATFORM_WINDOWS
#include <windows.h>
#endif

#include <Swiften/Base/String.h>
#include <Swiften/Base/ByteArray.h>

namespace Swift {

static inline size_t sequenceLength(char firstByte) {
    if ((firstByte & 0x80) == 0) {
        return 1;
    }
    if ((firstByte & 0xE0) == 0xC0) {
        return 2;
    }
    if ((firstByte & 0xF0) == 0xE0) {
        return 3;
    }
    if ((firstByte & 0xF8) == 0xF0) {
        return 4;
    }
    if ((firstByte & 0xFC) == 0xF8) {
        return 5;
    }
    if ((firstByte & 0xFE) == 0xFC) {
        return 6;
    }
    assert(false);
    return 1;
}

std::vector<unsigned int> String::getUnicodeCodePoints(const std::string& s) {
    std::vector<unsigned int> result;
    for (size_t i = 0; i < s.size();) {
        unsigned int codePoint = 0;
        char firstChar = s[i];
        size_t length = sequenceLength(firstChar);

        // First character is special
        size_t firstCharBitSize = 7 - length;
        if (length == 1) {
            firstCharBitSize = 7;
        }
        codePoint = firstChar & ((1<<(firstCharBitSize+1)) - 1);

        for (size_t j = 1; j < length; ++j) {
            codePoint = (codePoint<<6) | (s[i+j] & 0x3F);
        }
        result.push_back(codePoint);
        i += length;
    }
    return result;
}


std::pair<std::string,std::string> String::getSplittedAtFirst(const std::string& s, char c) {
    assert((c & 0x80) == 0);
    size_t firstMatch = s.find(c);
    if (firstMatch != s.npos) {
        return std::make_pair(s.substr(0,firstMatch),s.substr(firstMatch+1,s.npos));
    }
    else {
        return std::make_pair(s, "");
    }
}

void String::replaceAll(std::string& src, char c, const std::string& s) {
    size_t lastPos = 0;
    size_t matchingIndex = 0;
    while ((matchingIndex = src.find(c, lastPos)) != src.npos) {
        src.replace(matchingIndex, 1, s);
        lastPos = matchingIndex + s.size();
    }
}

std::vector<std::string> String::split(const std::string& s, char c) {
    assert((c & 0x80) == 0);
    std::vector<std::string> result;
    std::string accumulator;
    for (size_t i = 0; i < s.size(); ++i) {
        if (s[i] == c) {
            result.push_back(accumulator);
            accumulator = "";
        }
        else {
            accumulator += s[i];
        }
    }
    result.push_back(accumulator);
    return result;
}

std::string String::convertIntToHexString(int h) {
    std::stringstream ss;
    ss << std::setbase(16);
    ss << h;
    return ss.str();
}

int String::convertHexStringToInt(const std::string& s) {
    std::stringstream ss;
    int h;
    ss << std::setbase(16);
    ss << s;
    ss >> h;
    return h;
}


#ifdef SWIFTEN_PLATFORM_WINDOWS
std::string convertWStringToString(const std::wstring& s) {
    int utf8Size = WideCharToMultiByte(CP_UTF8, 0, s.c_str(), -1, NULL, 0, NULL, NULL);
    if (utf8Size < 0) {
        throw std::runtime_error("Conversion error");
    }
    std::vector<char> utf8Data(utf8Size);
    int result = WideCharToMultiByte(
            CP_UTF8, 0, s.c_str(), -1, vecptr(utf8Data), utf8Data.size(), NULL, NULL);
    if (result < 0) {
        throw std::runtime_error("Conversion error");
    }
    return std::string(vecptr(utf8Data), utf8Size-1 /* trailing 0 character */);
}

std::wstring convertStringToWString(const std::string& s) {
    int utf16Size = MultiByteToWideChar(CP_UTF8, 0, s.c_str(), -1, NULL, 0);
    if (utf16Size < 0) {
        throw std::runtime_error("Conversion error");
    }
    std::vector<wchar_t> utf16Data(utf16Size);
    int result = MultiByteToWideChar(
            CP_UTF8, 0, s.c_str(), -1, vecptr(utf16Data), utf16Data.size());
    if (result < 0) {
        throw std::runtime_error("Conversion error");
    }
    return std::wstring(vecptr(utf16Data), utf16Size-1 /* trailing 0 character */);
}
#endif

}